Navigational Theory 6: Instinct

This theory suggests that the pigeons use instinct, not the thinking process, to guide them home. This is probably the least accepted theory, however, as it is easily reasoned away: As I have observed, the pigeons clearly make decisions as they are navigating. Even when they are initially circling to gauge their global positioning, they are making decisions. They may start out in a direction that is not accurate: However, in these rare situations, they often return to the point of release and re-assess their interpretations by circling again. And then once again they will start out in a direction they believe to be more accurate, and eventually gain accurate bearings.

Also, when the skies are overcast, though the pigeons might head off in the wrong direction, and other things in their environment may delay them, the pigeon is able to consistently adjust and re-assess its direction (clearly making a series of choices) and is able to locate proper direction and a safe return home.

Navigational Theory 2: Map & Compass

The “Map and Compass” Theory
This theory, called Kramer’s Map-and-Compass Model, suggests that pigeons navigate in environments that contain at least two “intersecting gradients,” which are used by the pigeons, to figure out which way home is. By comparing the gradient values at the loft and at the release site, the bird constantly assesses and reassesses the latitude and longitude in relation to where he needs to be to find home.

*Latitude; angular distance of any point on the surface of the earth north or south of the equator. The equator is latitude 0°, and the North Pole and South Pole are latitudes 90°N and 90°S, respectively. The length of one degree of latitude averages about 69 mi (110 km); it increases slightly from the equator to the poles as a result of the earth's polar flattening.

*Longitude; angular distance on the earth's surface measured along any latitude line such as the equator east or west of the prime meridian. A meridian of longitude is an imaginary line on the earth's surface from pole to pole; two opposite meridians form a great circle dividing the earth into two hemispheres.

*Source: The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2005, Columbia University Press.